1. Field of the Invention
The invention relates generally to excavators and more particularly to a self-propelled rotary excavating machine that cuts new drainage ditches and maintains existing drainage ditches with laser precision.
2. Discussion of the Background
Alluvial soils located on flood plains of streams need to be drained before they can be developed, for example, for agricultural uses.
The parcels of land to be drained are fitted into a general drainage plan for the entire acreage. Typically, the excavation of a drainage ditch was accomplished with draglines and dozers. The draglines were, typically, of various sizes, depending on the required excavation and the distance necessary to reach the excavation area. A further factor to consider was to place the excavated soil, known as spoil, in the vicinity of road or levee construction. Large drainage ditches required the use of a large dragline having a long boom. Smaller field and lateral ditches which feed into the larger drainage ditches were excavated by smaller draglines.
The use of the draglines either to form the drainage ditch or to dredge a preexisting drainage ditch requires the additional use of dozers to move and shape the resulting spoil into roads or levees or to spread it out in the adjoining fields as drainage ditches were being excavated.
During the early 1970""s, trackhoes became available to cut drainage ditches. Trackhoes are more efficient for excavating small ditches than are draglines. At that time, trackhoes were used for field drainage and other development that did not require the use of a large capacity machine. Trackhoes and draglines equipped with wide tracks can operate under very wet field conditions. However, a problem with using trackhoes and draglines in wet conditions is that leveling wet spoil will result in future crop losses in the affected area.
Also used to cut drainage ditches were rotary power ditchers. A rotary power ditcher is a device mounted on a tractor""s 3-point hitch driven by the power take-off shaft. The use of this device was usually for making a network of small water furrows cut in small natural drains and through field depressions connecting to the field ditches. In some instances, the small water furrows would extend up to a quarter of a mile in length. Attempting to move water run-off up to a quarter mile on nearly level or flat land via a small water furrow usually created several problems. Such problems occur during heavy rainfall when large volumes of water accumulate and flow across the field, thus, scouring the field in some areas. Water moving across a freshly cultivated field under these conditions will move silt into the field ditches. Some of the furrows will then be closed by silt, thus, resulting in water ponding in field depressions. The soil surrounding the ponded area then becomes saturated with water. The silt also forms silt bars in field ditches which reduce their drainage efficiency.
Drainage ditches which are filled with silt must be re-excavated so as to maintain efficient drainage of the field. Thus, there is a maintenance schedule for the regular clearing of the silt-filled drainage ditches. The annual ongoing and recurring high cost of ditch maintenance performed by slow moving hydraulic trackhoes and dozers was unacceptable.
Hydraulic trackhoes are more efficient than draglines in excavating and maintaining field and lateral ditches. However, the efficiency of hydraulic trackhoes is not comparable to the speed and efficiency of smaller tractor mounted rotary powered ditchers. The small tractor mounted rotary powered ditchers are suitable for cutting small water furrows to carry water run-off from field depressions to field drainage ditches.
Thus, there is a need for an efficient device for excavating water furrows which cuts a water furrow such that it does not fill-up with silt as quickly as do water furrows cut by preexisting devices.
The invention meets the aforementioned need to a great extent by providing a self-propelled rotary excavator that excavates a field drainage ditch in such a manner that it can be done swiftly, efficiently, economically, and which can reduce the need for periodic maintenance of the drainage ditch.
In one embodiment of the invention, the self-propelled rotary excavator includes a mobile platform, a lateral telescoping boom attached on one end to the mobile platform, and on the other end to a vertical telescoping boom to which is attached a rotary cutting device that includes an adjustable shield for directing the discharge of spoil.
In still another aspect of the invention, the self-propelled rotary excavator includes a laser control system to control the horizontal and vertical positions of the rotary cutter.
In another preferred embodiment of the invention, the self-propelled rotary excavator includes a vehicular chassis mounted on four wheels, each wheel having its own independent source of power.
The present invention provides a precision self-propelled rotary excavator with a cutting device capable of cutting deeply into the soil to make a deep drainage ditch in a rough terrain environment. The prior art does not disclose the use of a self-propelled rotary excavator that can operate over rough terrain with precise lateral and vertical rotor positioning while evenly distributing the spoil on the field. Furthermore, the self-propelled rotary excavator is able to operate where draglines and trackhoes cannot, and furthermore it can operate the larger, heavy rotary cutting device which is not possible with a tractor.
Another aspect of the invention is that it will evenly distribute wet spoil such that crop losses are avoided.
Still another aspect of the invention is the provision of the ability to clean and maintain an existing ditch without having to straddle the ditch.